In the modern society, the use of electronic products has become an indispensable part of the life, and necessities such as eating, clothing, living, traveling, teaching, and entertainment are correlated to electronic products. To facilitate carrying and using of the electronic products, the electronic products are designed to be light and thin. Usually, an electronic product has a key structure. To make the electronic product lighter and thinner, measures are taken to simplify configurations of a support structure and an elastic structure in the key structure, or reduce the heights of the support structure and the elastic structure. In this way, the height of the key is reduced and the volume of the entire keyboard is reduced, but the feel of a pressing stroke of the key may be lost. As a result, a user cannot determine whether pressing of the key is completed or uncomfortable pressing feel is generated, and therefore the user feels inconvenient.
To maintain a good feel of pressing of the key, US patent publication no. US20110203912 discloses a key structure in which an elastomer (Elastomeric Dome) is used together with a metal elastic piece (Metal Dome). When a key is pressed, the elastomer is first touched and pressed to deform, and subsequently, the metal elastic piece is touched and pressed, so as to maintain the pressing feel of the key. However, in the earlier patent, a protrusion structure at a lower surface of a key cap directly presses the metal elastic piece. In this way, noises may be generated during pressing. Moreover, both the key cap and the metal elastic piece are rigid structures, resulting in a rigid pressing feel. In addition, in the prior art, a key is usually mounted by first adhering a metal elastic piece onto a thin film switch and then disposing an elastomer on the metal elastic piece. In the assembly process, by the mounting method, the protrusion structure at the lower surface of the key cap may not be able to actually press the metal elastic piece due to an offset of a center point between the elastomer and the metal elastic piece, resulting in a failure in the key function or a change in the pressing stroke of the keyboard.
Therefore, how to maintain the pressing feel and comfort of a key and avoid an offset in mounting of an elastomer and an elastic piece of the key when the height of the key structure is reduced is a technical issue to be resolved by the present invention.